Power-transmission apparatus



W. C. REED. POWER TRANSMISSION APPARATUS.

APPLICATION FILED APR 19, 1920. v

Patented July 4, 1922. A

In men for 02m Cff q an if it a a i I is. i

POWER-TRANSMISSION APPARATUS.

Application filed April 19, 1920.

To all whom it may concern:

Be it known that I, l VALTER C. Rnnn, a citizen of the United States,residing at Dal ton, in the county of Berkshire and State ofMassachusetts, have invented certain new and useful Improvements inPower-Transmission Apparatus, of which the following is a specification.

The present invention relates to power transmission apparatus, and moreparticularly to apparatus for connecting the driving power of a domesticwashing machine to a pump employed therein.

As the washing machine is continuously driven from a main driving shaft,and as the pump is needed only at short and comparatively rare periods,to reduce the water in the machine, it is desired to provide means toconnect and disconnect the pump shaft and the main driving shaft thisburden being added when the main shaft is running at full speed. Asmechanism of the type stated is light, driven by a high speed motor, andmust be essentially inexpensive in construc. tion and ruggedly durablein use, it is an object of the present invention to provide means bywhich the maximum load of the pump can be picked up quietly and withoutracking the mechanism. It is accordingly an object of the presentinvent-ion to provide a new and improved yielding connection between thedriving shaft and the separate pump mechanism that shall be extremelysimple in construction and yet adapted for the purpose. To this end, afeature of the invention resides in providing a stationary sleeve whichconstitutes a tubular bearing for the'rapidly rotating driving shaft,and a moving sleeve that is rotatably and slidably mounted on saidstationary sleeve, which thus constitutes a bearing for the movingsleeve. The latter has at its end a stud adapted to engage the freetangentially or radially projecting end of a helical driv ing springwhich is wound around thedriving shaft next to the stationary sleeve,and has its other end secured to the shaft. The pump is driven by asprocket chain from the moving sleeve; When the latter is shiftedendwise so that its stud gets into the path of the whirling projectingend of the spring, it engages that end, gradually tightens the springcoil by its inertia, and gradually picks up the speed of the spring asthe spring gets stiffer. All of this operation Specification of LettersPatent.

Patented July 4t, 1922.

Serial No. 374,843.

thus described as being gradual is really very quick, but it issufiiciently yielding and gradual as compared with a positive,unyielding, connection to be well adapted to the needs of a washingmachine.

Other objects of the invention are to improve power transmissionapparatus of the above-described character, rendering it simple, easilyoperable, noiseless, effective, cheap to manufacture and to assemble anddurable. An illustrative embodiment of the invention 1s herein shown anddescribed.

It is intended that the patent shall cover, by suitable expression inthe appended claims, whatever features of patentable nov elty exists inthe invention disclosed.

In the accompanying drawings:

Figure 1 is a plan, partly in section, of a washing machine drivingapparatus con- StllCtfiCl according to the present invention; an

Figure 2 is an end elevation, showing the apparatus connected so as todrive a washing machine centrifugal pump.

The, washing machine, not shown, but typified by the fragment of frame1, gear casing 2, and shaft 8, is driven from a main driving shaft 4through a worm and a gear enclosed, according to well-known practice, ina worm-gear housing. The main shaft 4 is. continuously driven by motor6. A centrifugal pump 8 is provided with a shaft 10 that it is desiredto drive occasionally from the main driving shaft 4:. To this end, theshaft 10 is provided with a sprocket wheel 12 that is connected by asprocket chain 1% to a driving sprocket wheel 16, adapted to be drivenfrom the main driving shaft by the spring clutch now to be de scribed.The sprocket wheel 16 is fixed upon a sleeve 18 that is slidably androtatably mounted around the main driving shaft and that is at its endprovided with a driven stud 20 which constitutes one of the clutchmembers. In the present instance the sleeve 18 is mounted, not directlyupon the driving shaft 4, but upon a tubular extension of the gearhousing 21 that surrounds the shaft, constitutes a bearing therefor andserves also to retain packing and oil within the worm gear housing. Thelength of the chain is such as to permit the lateral displacement whichis incidental to the sliding of the sleeve upon the shaft withoutrequiring that the chain be disengaged from the sprocket wheels. Thedriven stud 20 projects parallel with the shaft and is arranged toengagewith the free outward projecting end 22 of a helical spring 24. which iswound toward it for a few turns about the driving shaft 4 from ananchorage of its other end to theshaft at 26.

The outstanding end may preferably be hooked as at 23, by being bentinto approximate parallelism with the circumference of the shaft at adistance far enough out therefrom to be Outside of the radial distanceof the position of stud 20. This prevents the end of the. spring fromslipping past its engaging stud as the outstanding end'of the springbecomes shortened, when engaged, by the spri'ngbeing wound more aroundits shaft. Upon the sleeve 18 being slid along shaft 4 to the left, Fig;1, therefore, during the rotation ofthe shaft the sprocket 'wheel16 willcome into the plane of sprocket l2, and the stud 20 will move into thepath ofrotation of the end 22 of the spring so as to be engaged thereby;the hook 23 will catch the stud as illustrated; and thereupon therotative movement of the driving shaft will be transmitted yieldingly,through the spring, the sprocket sleeve and the chain to the pump shaft10. The operation is effected easily, gently and noiselessly and isattended with no injurious effects. The pump has to get'up-its fullstandard speed very quickly and the yielding effect helps tota-keupwhatevershock may be imposed, rendering it particul'arly adaptable tothe requirements heretofore stated.

The above-described mechanism is associated preferably withv aslip-clutch connection and a fiexiblecoupling which may be of anysuitable design between the motor 6 and the main driving shaft 4. Theflexible coupling is shown at 28 connecting the main driving'shaft toone element 30 of the slip clutch. The other element 32 of the clutch isdirectly connected to the motor. In case of'need'at the moment when thesleeve 18 is movedto the left Fl 1, to connect the pump to the drivingshaft, the friction clutch will yield, tending further to reduce theinitial shock, and incidentally also protecting the motor, The flexiblecoupling 28 which may be a length of heavy steam hose acts to compensatefor possible transverse slight displacements of the shaft 4, so thatpower may be transmitted to the washing machine and to the pumpsimultaneously without strain,

and acts further to take up shocks due to vibration. There is no partwhich does not receive shock through an elastic medium,

when the stud 2O engagesspring 2a.

The sleeve 18 is adapted to be moved to the left, to engage its studwith the free pnojectingend 22of the spring, and to the right. to causetheir disengagement, on which occasion the stud slips out sidewise fromthe hook 23, by a pawl 34 having a projecting portion 36 lying in acircumferential groove 38 on the sleeve. The pawl 3% is pivoted to arocking arm 4-0 that is offset at right angles from the pivotal portiona2 of a pump control rod. The control rod 42 is provided with a handle(indicated at the left, Figure 2) whereby it may be rocked to either oftwo extreme positions indicated in full and dotted lines in Fig. 1. Inthe full line position, the pump is driven from the driving shaft. Inthe dotted line position, the pump is inactive. A tension spring 44 isfastened at one end to the offset arm at) and at its other'end is fastto the frame'of the machine, in such position that the straight linejoining the ends-of the springrswings past a dead center position withrespectto the rocking arm 40 of the pump control rod Q2. The 7 springthus acts to maintain securely the arm vetO in either ofits illustratedpositions, eliminating the possibility of the pump accidentally startingor stopping. The pawl 3a is supported by a bracket 46 secured to thegland 21. V v

In consequence, the sleeve 18 is held without friction while the pump isnot in use, although it surrounds and is movable along the main shaft 4;and when moved it is held in engagement by the spring a4 and by thehooked end 23 of the clutch, and is subjected to wear only while thusengaged. 'The'interior of the stationary sleeve 21 may: or may not be abearing for-the shafts, at the pleasure of'the designer, there beingshown a slight clearance for'the shaft in Figure *1; and this stationarysleeve 21 may be readily designed as a fiXedpart of other mechanism, thesame beingused in the present case as a gland to hold packing-in place.

The construction of the whole; is extremely simple, as regards expense,as is'manifest by. observing the extreme simplicity of the clutch springarrangement, and introduces an element of elasticity by which the pump110 can be connected abruptly, so far as the operator is concerned, atany time without the complication ofan ordinary clutch and without theordinary incidental shock. V \Vhen the apparatus is designed for thepurposes 115 stated, the spring may have about'five turns of its helixon the shaft, and has abundant strength and elasticity if made up ofwire about in diameter;

The invention having been thus described .120

what is claimed as new is:

1. In combination, a shaft, a; sleeve rotatably and slida-blysurrounding it, having a. driven stud, a helical driving spring loose onthe shaftv with one end fastened. to the shaft and with its-other endfree and extendingoutw-ar-d from the shaft in direction to engage anddisengage freelya bodyrotating about the shafts axis, and means forsliding the sleevealong the shaft to move the driving stud into and outof engagement with the free end of the spring.

2. In combination, a shaft, a sleeve rotatably and slidably surroundingit, having a stud projecting parallel with the shaft, a helical springwound around the shaft, having one end fastened thereto and its otherend extending outward from the shaft and formed as a hook outside of theposition of and adapted to engage the stud; and means for sliding thesleeve along the shaft to move the stud into engagement with theprojecting end of the spring between said hook thereon and the shaft,whereby the hook is drawn inward into engagement with the stud when theshaft rotates, and to slide the sleeve in the other direction with thestud slipping in the axial direction out from engagement with thespring.

3. In combination, transmission mechanism comprising a main drivingshaft; a tubular stationary sleeve surrounding it; a second sleevesurrounding the shaft, rotatable and slidable on the first sleeve; meansto slide the second sleeve on the first sleeve; a

wire spring coiled loosely around the shaft next to the sleeves, havingone end fast to the shaft and its other end free and outstandingtherefrom in position for engagement by the second sleeve when thelatter is slid toward it.

Signed at Pittsfield, Massachusetts, this sixteenth day of April, 1920.

WALTER C. REED,

